Scientists taking stomach samples (Photo Credit:South Tyrol Museum of Archaeology)

When two German hikers stumbled upon a dead body buried in ice in the Italian Otzal Alps in 1991, they had no idea that the pristine remains were those of a male who had inhabited Earth almost 5,300 years ago. Named Ötzi, after the mountains where he had lain for thousands of years, the Iceman is Europe’s oldest-known natural human mummy.

Over the years, researchers have been able to uncover many fascinating details about the Copper Age glacier mummy, who now resides in Italy’s South Tyrol Museum of Archaeology. They believe Ötzi was most likely 5 feet, 5 inches tall, and had brown eyes and shoulder- length dark hair. Though he had a lean physique, CT scans revealed that the ancient human suffered from arthritis, and had rotten teeth, and hardened plaque around his heart, which put him at risk for a heart attack.

However, the 45-year-old did not die of natural causes – he was murdered! The gruesome finding came to light in 2001 after an X-Ray revealed a small arrowhead in Ötzi’s left shoulder. This, along with the blunt trauma on his head, led scientists to conclude the ancient human was most likely shot with multiple arrows and beaten to death. Given that his “valuables,” which included fur clothing and a copper axe, were not stolen, researchers suspect the murderer was not a thief but someone that may have had a personal grudge against the Iceman.

Artist’s rendering of Ötzi (Photo Credit: A.Ochsenreiter/South Tyrol Museum of Archaeology, Institute for Mummies and the Iceman)

The one thing that remained a mystery was the 5,300-year-old human’s diet. Understanding what the Iceman ate on a regular basis would help determine how he survived the harsh mountainous habitat and, more importantly, provide insight into our ancestors’ dietary habits. However, researching the contents of his stomach proved challenging, given that the organ had shifted during the mummification process and nobody had any idea where it was.

Since opening up the body could damage the precious mummy, researchers had to content themselves by analyzing Ötzi’s small and large intestines, which revealed some cooked meat and an unidentifiable grain. The breakthrough finally came in 2009, after a CT scan identified the location of Ötzi’s stomach. Frank Maixner of the Eurac Research Institute for Mummy Studies in Bolzano, Italy, said, "The stomach material was, compared to previously analyzed lower intestine samples, extraordinarily well preserved, and it also contained large amounts of unique biomolecules such as lipids, which opened new methodological opportunities to address our questions about Otzi's diet."

The Iceman's gastrointestinal (GI) tract preservation and content texture (Photo Credit: Institute for Mummy Studies\Eurac Research\Frank Maixner)

Using a combination of classical microscopic and modern molecular approaches, Maixner’s team began the long, arduous process of discerning what our ancient ancestor may have chowed down on before his untimely death. The results of their study, published in the journal Current Biology on July 12, 2018, revealed that half of Ötzi’s stomach was composed of adipose fat, which the researchers believe came from ibex, an alpine goat. The presence of striated muscle fibers confirmed that the Iceman had consumed meat which had been air-dried or minimally-heated. That’s because meat fibers only retain their structure if cooked at temperatures below 140 degrees Fahrenheit (60 degrees Celsius). They also found evidence of non-milled einkorn wheat and red deer. According to Maixner, given that the Iceman’s freezing alpine habitat would need a lot of calories to survive, the greasy last supper “totally makes sense.” The high-fat diet also explains the hardened plaque around Ötzi heart.

Curiously enough, Ötzi also consumed a poisonous fern called bracken. Albert Zink, Head of the Eurac Research Institute for Mummy Studies, says while it could have been ingested unintentionally, “It looked like he consumed it [the bracken] quite regularly, which would make it more like a kind of drug he took against parasites.” The team isn’t done with Ötzi yet. They next plan to study the bacteria inside his stomach and compare it to the one in modern humans to see if, and how, it may have evolved over the thousands of years.